In worksites such as, for example, quarries, loading machines including wheel loaders, backhoe loaders, track-type loaders, and other types of loaders are used to load material onto haul vehicles. Because the loading machine is an integral part of the quarry operation, it is usually under control of the quarry. Typically, the haul vehicles (e.g., dump-trucks) are not owned by the quarries, but by individual customers. This usually requires quarry personnel to interact with each haul vehicle operator every time they come to the quarry to determine who the customer is and the type and the amount of material desired by the customer. Also, payload information such as, for example the desired type and amount of material for each haul vehicle, needs to be communicated to the quarry personnel who operate the loading machine. Verbal interaction between quarry personnel and haul vehicle operators can be time consuming and prone to error.
The haul vehicle typically drives into the quarry through an entrance where the haul vehicle is identified by quarry personnel. The quarry personnel then dispatch a loading machine to meet the haul vehicle at a particular site to load a desired amount of material onto the haul vehicle. To determine if the haul vehicle has been loaded with the desired amount of material, the haul vehicle is usually driven onto scales and weighed. If the haul vehicle is overloaded, some of the material must be removed. Similarly, if the haul vehicle is underloaded, more material must be added. In these overloading and underloading situations, the haul vehicle must re-cycle through the quarry, returning to the loading site so that the amount of material in the haul vehicle can be modified and to the scales so that the modified payload can be verified. This re-cycle process costs additional time, fuel, and money.
Once the final amount of the material loaded onto the haul vehicle is measured, the measurement is then used for billing and other purposes. These administrative tasks require quarry personnel to correctly match each haul vehicle with a corresponding customer so that an appropriate bill can be delivered to the haul vehicle operator before the operator leaves the quarry. These tasks can also be prone to error. For example, the quarry personnel may deliver the bill to the wrong haul vehicle operator.
One method of improving the efficiency of loading operations at a worksite is disclosed in U.S. Pat. No. 5,848,368 (“the '368 patent”) issued to Allen et al. The '368 patent discloses a method for controllably loading haul vehicles with a material by a mobile loading machine. Each of the haul vehicles has a identification tag located on it. An identification tag reader, located on the mobile loading machine, reads the identification tag and responsively produces a haul vehicle identification signal. The mobile loading machine accesses a customer data file, which includes at least a desired amount of material. The customer data file and the haul vehicle identification signals are compared. A load command signal is produced in response to the comparison. The mobile loading machine loads the haul vehicle in response to the load command signal. The mobile loading machine includes a payload monitoring system to determine the actual amount of material being loaded onto the haul vehicle by the mobile loading machine. The determined actual amount of material is compared with the desired amount of material. Once the value for the actual amount of material loaded onto the haul vehicle is determined, the customer data file is updated accordingly and a customer communication such as a bill including the value of the actual amount of material is prepared in response to the updated customer data file.
While the method of the '368 patent may improve the efficiency of loading operations at a worksite by automating many of the quarry-related tasks, its effectiveness may be limited. Specifically, because the method of the '368 patent relies on a payload monitoring system included in the mobile loading machine, the actual amount of material loaded onto the haul vehicle may be inaccurately determined. In particular, over time, the payload monitoring system may drift away from a calibrated setting to give erroneous readings resulting in an over-reporting or under-reporting of the actual amount of material loaded onto the haul vehicle. These misreported results may persist from the payload monitoring system until the payload monitoring system is re-calibrated. Further, because each mobile loading machine may be associated with a different payload monitoring system, different measurements for the same amount of material may be reported, thus leading to inconsistent measurements of the material loaded during different loading operations at the same worksite.
The method of the '368 patent may also be limited in its efficiency. In particular, because the presence of a haul vehicle may be determined by an RFID reader included in a mobile loading machine, it may be difficult to keep track of how many haul vehicles are at the worksite and how much time the haul vehicle remains at the quarry while for a loading operation. For example, two haul vehicles may be present at the quarry for loading, and each haul vehicle may be recognized by a different mobile loading machine. Because the mobile loading machines may be unaware of when the haul vehicles arrived at or left the quarry and because the presence of both haul vehicles may be unknown to either mobile loading machine, customers may be unable to accurately assess the productivity of the quarry's loading operations.
The disclosed system is directed to overcoming one or more of the problems as set forth above.